function s1 () {
  return new Promise(resolve => {
    setTimeout(() => {
      console.log('s10')
      resolve()
    }, 1000)
  })
}

function s2 () {
  return new Promise(resolve => {
    setTimeout(() => {
      console.log('s20')
      resolve()
    }, 1000)
  })
}

function s3 () {
  return new Promise(resolve => {
    setTimeout(() => {
      console.log('s30')
      resolve()
    }, 1000)
  })
}

export async function setTimeAsync () {
  await s1()
  await s2()
  await s3()
}
